Yeah, sure! Any game from psn MUST be decrypted for NPRDM, and this has nothing to do with CFW4.21. New CFW allows you to run higher FW games, NOT FREE psn games.

You can play Oddworld: SW only if you have new keys, decrypt unlock edat so you unlock game and then you can play.
Ofcourse, you need rap file to fix edat too, and rap means someone has to buy it. Same with Journey or any other game that is not C00 type.

On the other hand, I did fix WALKING DEAD Ep.1 & 2 for new CFW 4.21. Tested and working. There is already new patch update 1.03, so you must update game to last patch. Probably for new episodes adding. I will release it tomorrow.